Thread tensioning device



NOV. 21, 1933. B, JAVERY ET AL 1,936,452

THREAD TENS IONING DEVICE Filed Feb. 13, 1929 m7? 0715 50/1 /K 5 Jm c' 7 0 J ./a My Mat/Q2 Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE 1,936,452 THREAD TENSIONING DEVICE Application February 13, 1929. Serial No. 339,713

2 Claims.

Our invention relates to thread tensioning devices, and has for its object to provide a device of this class which is adapted to create the desired amount of tension in a thread passing through the device without causing any appreciable frictional or rubbing effect on the thread.

Olll' improved tensioning device is particularly adapted for handling threads, or other filamentary material, of a silky nature in which the o fibers constituting the filament are very fine, so that rubbing the thread in the direction of its length will cause the fibers to separate themselves from the filament, which of course is undesirable. Filamentary material of this nature is now being produced synthetically, without spinning, the well known rayon thread belonging to this class of material, and it has been found that thread tensioning devices which impose an actual frictional drag on the thread are entirely unsuited for handling such fragile material.

According to the present invention, we provide an improved thread tensioning device in which the thread passes around a rotatably mounted pulley adapted to turn freely with the 5 thread, the tension effect being obtained by applying a variable frictional force to the pulley itself. Furthermore, in our improved device the pulley is so mounted that the filament first engages the pulley in one plane and leaves the pulley in another plane, so that in passing around the pulley there is no chance for different portions of the same filament to rub against each other. A still further advantageous feature of our device resides in the provision of a guard associated with each pulley which prevents the filament from freeing itself from the pulley even in the event the filament should overrun upon a stoppage in the movement thereof around the pulley. The above and other advantageous features of our invention will hereinafter more fully appear, reference being had to the accompanying drawing in which Fig. 1 is a plan view of a number of our improved thread tensioning devices arranged in a row.

Fig. 2 is a plan view showing one of the devices on an enlarged scale.

Fig. 3 is a view in front elevation of the device shown in Fig. 2.

Fig. 4 is a view in end elevation of the device shown in Fig. 3.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, our invention is il- 55 lustrated as being employed in connection with a number of spools or yarn packages 1 from which it is desired to draw threads 2 for any suitable purpose, as for winding on a large spool or warp beam, preparatory to weaving. For the purpose of guiding the threads 2 as drawn from the packages 1, a supporting member 3 is arranged in front of the row of packages 1, which member 3 carries a number of spaced thread eyes 4 through which the individual threads 2 pass. Each thread eye 4 has associated therewith one of our improved tensioning devices, each generally designated by the reference numeral 5, and as the tensioning devices 5 are identical in construction only one need be described in detail.

Each tensioning device comprises a pulley 6 loosely mounted on a spindle '7 and, as shown in Fig. 3, the pulley 6 provides a V-shaped groove 8, the sides of which are covered with a smooth material of a frictional nature, such as rubber, as indicated at 9. The spindle '7 which supports the pulley 6 is supported at an angle from the vertical, as viewed in both Figs. 3 and 4 by means of a bracket 10 secured to one leg 3a of the supporting member 3. The bracket 10 provides an opening for receiving a reduced end of the spindle '7 which is threaded to receive a nut 11 for holding the spindle '7 in position. The bracket 10 projects beyond the spindle '7 at one side and is bent upwardly to provide an ear 12 which extends forwardly and serves to support a thread-eye 13 for guiding the thread 2 from the next adjacent tensioning device 5, as indicated in Fig. l.

The bracket 10 also provides an annular portion 14 which encircles the pulley 6, although spaced therefrom sufhciently to permit free rotation of the pulley 6. As shown in Fig. 3, the annular guide portion 14 is bent towards the leg 3a of the supporting member 3, so that the outer portion of the guide 14 is substantially flush with the lower rim of the pulley while the inner portion thereof substantially coincides with the bottom of the groove 8 in the pulley.

When it is desired to draw threads 2 from the packages 1, each thread 2, after being passed through the eye 4 is looped around a pulley 6 as shown in Fig. 2, after which it is passed through the eye 13 of the next adjacent tensioning device 5. Therefore a pull on the thread in the direction of the arrow will cause the thread to engage the bottom of the groove 8 of the pulley. However, due to the inclination of the spindle '7 the thread will engage the far side of the pulley 6 in one plane and will leave the near side of the pulley 6 in another plane spaced from the first 110 plane, so that there is no possibility of different portions of the same thread 2 moving in opposite directions, engaging each other where the thread crosses as viewed in plan in Fig. 2. In other words, as the thread leaves the pulley it takes a downward direction with respect to the axis of the eye 4, the direction of the thread substantially coinciding with the outer portion of the guard 14.

As the thread is drawn from its package 1 through the eye 4 and around the pulley 6, it

causes the pulley to rotate on its spindle '7 and since the pulley 6 is made of light material, preferably wood, the pulley travels at a peripheral speed which is substantially the same as the speed of the thread. In passing around and driving the pulley '7, the movement of the thread 2 is checked just enough so that there is a slight tension imparted to the thread so that it will wind evenly and compactly on the spool or beam onto which it is being drawn. Should it be desired to increase the amount of tension on the t read 2, this may be readily accomplished by placing a light washer 15 on the spindle 7, the Washer 15 resting on the upper surface of the pulley 6. The washer 15 is provided with an opening 16 having a straight portion which corresponds to a fiat portion 17 on the spindle 7 so that the washer 15 can not turn with the pulley 6 on the spindle 7. Therefore the Washer bears on the upper surface of the pulley 6 and exerts enough frictional force thereon to obtain the desired tension,

As We previously pointed out, the annular guard portion 14 of the bracket 10 encircles the pulley 6, as shown in Fig. 2, and this guard portion 14 prevents the thread from falling away from the pulley when the drawing of the thread is interrupted. Due to the fact that filamentary material like rayon thread possesses considerable stiffness in the direction of its axis, the thread would tend to run out from the eye 4, as indicated by dotted lines, should the draft on the thread be interrupted and it is obvious that the guard portion 14 will effectively prevent the thread from freeing itself from the pulley 6 and dropping down when this occurs.

From the foregoing it is apparent that by our invention there is provided an improved thread tensioning device that is particularly adapted for handling thread of a fragile nature in which the fibers tend to separate themselves when the thread is subjected to a friction along the length of the thread. In passing around our improved device, different portions of the thread will remain well separated where these portions cross each other at the ends of the loop, so that no chafing can occur at this point. Furthermore, the guard associated with the pulley effectively prevents the thread from freeing itself from the pulley when it overruns following a sudden stoppage in the movement of the thread.

We claim,

1. In a device of the class described, a grooved pulley free to rotate about an axis, in response to a draft on a thread passing around said pulley and an annular guard surrounding said pulley and extending beyond the periphery thereof for preventing said thread from falling away from said pulley when the draft on the thread is interrupted, said guard being skewed with respect to the plane of the pulley to avoid contact with said thread during normal operation and to direct said thread into the pulley groove when draft isagain placed on the thread after having been interrupted.

2. In a device of the class described, a grooved pulley free to rotate about an axis, in response to a draft on a thread passing around said pulleyin a substantially horizontal plane and an annular guard surrounding said pulley adaptedto prevent said thread from falling away from said pulley when the draft on the thread is interrupted and the thread partially leaves the groove in said pulley.

FRANK B. JAVERY. ARMON J. JAVERY. 

